The stability during the storage between EB exposure and post- exposure bake (PEB) of the chemically amplified resist containing diphenylamine (DPA) was discussed. The large dimension change of 0.15 micrometer L/S pattern with 14 (mu) C/cm² EB dose was observed within 1 hour in a vacuum due to the deprotection reaction. The stability of the resist properties in an atmosphere before PEB (PED instability) depends on the time during which the exposed resist is stored in a vacuum. Keeping the exposed resist in a vacuum for more than about 20 minutes makes PED instability good. This seems to be caused by a dark reaction for about 20 minutes, which occurs in addition to the deprotection reaction and realizes equilibrium between DPA and acid generated by EB exposure. This mechanism by which DPA acts as a superior stabilizing base additive is supported by the time dependence of surface resistance for the resist in an atmosphere.

Date Published: 7 July 1997
PDF: 8 pages
Proc. SPIE 3049, Advances in Resist Technology and Processing XIV, (7 July 1997);

Published in SPIE Proceedings Vol. 3049:
Advances in Resist Technology and Processing XIV
Regine G. Tarascon-Auriol, Editor(s)